21838669 has 2 divisors, whose sum is σ = 21838670. Its totient is φ = 21838668.

The previous prime is 21838651. The next prime is 21838679. The reversal of 21838669 is 96683812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19980900 + 1857769 = 4470^2 + 1363^2 .

It is a cyclic number.

It is not a de Polignac number, because 21838669 - 2⁵ = 21838637 is a prime.

It is a super-2 number, since 2×21838669² = 953854927383122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21838639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10919334 + 10919335.

It is an arithmetic number, because the mean of its divisors is an integer number (10919335).

Almost surely, 2^21838669 is an apocalyptic number.

It is an amenable number.

21838669 is a deficient number, since it is larger than the sum of its proper divisors (1).

21838669 is an equidigital number, since it uses as much as digits as its factorization.

21838669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 43.

The square root of 21838669 is about 4673.1861721956. The cubic root of 21838669 is about 279.5173189132.

The spelling of 21838669 in words is "twenty-one million, eight hundred thirty-eight thousand, six hundred sixty-nine".